Boathook
Well-Known Member
My new to me 'toy' has had the aluminium framed glass windows removed and replaced with acrylic.
It seems that the windows are bedded down on an adhesive / sealant with M3 machine screws every 5" or so. M3 is ok but the nuts are really awkward and there are leaks through the holes that the screws go through. I will eventually bed the new fixings in with a butyl sealant.
I'm wondering whether to go up to M4 machine screws, but how large would I have to drill the acrylic so that the M4 won't crack the acrylic, 4.5mm or even 5mm diameter ?
Another option is that I stay with M3 and get some Big Heads Sighted internally threaded nut | ST38 | bigHead® Bonding Fastener made specially for M3, M4 being the smallest they list. These fittings would allow me to tighten up all the screws without assistance.
I have considered M3 rivet nuts but they are 9mm long and the GRP I'm 'bolting' through is only 6mm.
Unfortunately I don't have any pictures to share, but does any one have other, preferably sensible, ideas / suggestions ? I'm looking at around nearly 250 of the things !
It seems that the windows are bedded down on an adhesive / sealant with M3 machine screws every 5" or so. M3 is ok but the nuts are really awkward and there are leaks through the holes that the screws go through. I will eventually bed the new fixings in with a butyl sealant.
I'm wondering whether to go up to M4 machine screws, but how large would I have to drill the acrylic so that the M4 won't crack the acrylic, 4.5mm or even 5mm diameter ?
Another option is that I stay with M3 and get some Big Heads Sighted internally threaded nut | ST38 | bigHead® Bonding Fastener made specially for M3, M4 being the smallest they list. These fittings would allow me to tighten up all the screws without assistance.
I have considered M3 rivet nuts but they are 9mm long and the GRP I'm 'bolting' through is only 6mm.
Unfortunately I don't have any pictures to share, but does any one have other, preferably sensible, ideas / suggestions ? I'm looking at around nearly 250 of the things !